The ratio of the geometric mean and arithmetic mean of two numbers is 3:5, find the ratio of the smaller number to the larger number.

Respuesta :

Answer:

[tex] \frac{1}{9} [/tex]

Step-by-step explanation:

Let the numbers be x,y, where x>y

The geometric mean is

[tex] \sqrt{xy} [/tex]

The Arithmetic mean is

[tex] \frac{x + y}{2} [/tex]

The ratio of the geometric mean and arithmetic mean of two numbers is 3:5.

[tex] \frac{ \sqrt{xy} }{ \frac{x + y}{2} } = \frac{3}{5} [/tex]

We can write the equation;

[tex] \sqrt{xy} = 3 [/tex]

or

[tex]xy = 9 - - - (2)[/tex]

l

and

[tex] \frac{x + y}{2} = 5[/tex]

or

[tex]x + y = 10 - - - (2)[/tex]

Make y the subject in equation 2

[tex]y = 10 - x - - - (3)[/tex]

Put equation 3 in 1

[tex]x(10 - x) = 9[/tex]

[tex]10x - {x}^{2} = 9[/tex]

[tex] {x}^{2} - 10x + 9 = 0[/tex]

[tex](x - 9)(x - 1) = 0[/tex]

[tex]x =1 \: or \: 9[/tex]

When x=1, y=10-1=9

When x=9, y=10-9=1

Therefore x=9, and y=1

The ratio of the smaller number to the larger number is

[tex] \frac{1}{9} [/tex]